公开(公告)号：US3576506A

公开(公告)日：1971-04-27

申请号：US3576506D

申请日：1968-04-24

Applicant: BELL TELEPHONE LABOR INC

Inventor： REYNOLDS ROBERT L ,  SYKES ROGER A

IPC: H03H9/56 ,  H03H9/00

CPC classification number: H03H9/566

Abstract: Monolithic crystal filters forming respective resonators from a crystal wafer and three or more electrode pairs which are sufficiently massive and spaced far enough so that the otherwise undisturbed coupling between one resonator and any other resonator is such that there exists a zero-impedance-resonance to zero-impedance-resonance frequency range less than one-third the smallest antiresonant-to-resonant frequency range of one of the two-coupled resonators, have at least one pair short circuited. The short-circuited pair is tuned by appropriate mass loading so that its observed minimum-impedance frequency corresponds to the desired midband frequency of the filter.